SSB-Electronic GmbH 5055

The ACS 2004-N (N-Female) antenna control system allows the selection of four different antennas for all amateur bands from 80 m to 70 cm over a single coaxial cable. It consists of the AC-2004B control unit and the water protected outdoor unit AS-2004 switch. Both devices communicate over a single feed cable which additionally allows the powering as well as the sequencing of a preamplifier such as our SP Series or MHP series of preamplifier on any or all of the 4 antenna ports. In addition, a sequence step is also provided for power amplifier control.

For the first time a complete antenna switch with preamplifier and amplifier control is built into one unit.

Preamplifier and power amplifier sequencing can be activated by either a ground on transmit or by applying + 5...12 VDC on the appropriate pin on the D-sub 9 rear panel socket.

Installation Information:

Up to four antennas can be connected to the AS-2004 (mast-mounted) switch. Selection of the desired antenna is accomplished via the AC-2004 control unit selector switches.

If one of our preamps is connected to one of the antennas selected, voltage can be supplied to the preamplifier by holding in the antenna selector switch a little longer.

Preamp Sequencing Options:

• When using our SP-600, SP-200, SP-222 or SP-70 Preamplifiers and RF Output is <= 100 W, you can allow these preamps to RF-Sense (VOX Mode) and no further connections are necessary. A better installation method would be to wire the AC-2004 Control unit PTT input to your transceivers PTT control line and the preamp would switch out of line whenever your rig is placed in transmit.
• The MHP (non R models) series of preamplifiers allow voltage feed via the coaxial cable and require the use of sequencing in all cases.

The SP series of preamplifiers require sequencing when the RF power output of the transceiver or linear amplifier exceeds 100 W. Sequencing of both the preamplifier and RF power amplifier is accomplished by simply wiring the AC-2004 Control Unit PTT input to your transceivers PTT control line and wiring the RF Amplifiers PTT input to the AC-2004 amplifier PTT control pin on the rear panel D-Sub 9 socket.

WARNING:

Some solid state linear amplifiers even though they provide a PTT input do not disable their RF-Sense (VOX) capability. This means that whatever the linear sees first which is the RF from the transceiver will take precedence over PTT control. This has to be disabled so that true PTT control of the linear amplifier can take place. It is accomplished by a very simple modification involving the removal of one capacitor. Usually it just has to be clipped out.